The downside of becoming known to the NSA is that you can get caught up as an "associate" in someone's drug, criminal or terrorism investigation, and you had no idea that the person was doing anything like that. You might even have no idea that the person exists, since the NSA is "allowed" to go out some number of degrees of freedom from the supposed suspect.
The downside of becoming known to criminals is that you can fall victim to criminal schemes. You don't even have to be known by name or association, your device just has to be discovered; owning it is the all too easy next step. You can be known by installing malware (see the articles on phone downloaded apps), or by criminals seeing your communication on the open internet and becoming aware of you.
That's what I'd tell my friends, if any of them were still listening.
I don't have a clear idea of what the downside is if the NSA gets my information. So I haven't bothered to download Signal.
I don't mean this in the disparaging way that folks who use "If you have nothing to hide, you have nothing to worry about" do, but the truth is that most people assume that Facebook and Google know a huge amount about them already, and that if the NSA wants to find out about them, so what?
Maybe a better education campaign to convince those people who don't believe that they have anything to hide why they need apps like Signal would be an important first step.
What I want people to consider, frequently, is whether or not we should fight these anti-privacy measures not because anything is wrong now, but because of who might eventually be given access to that information. We should fight to make sure that tools to oppress and enforce terrible regimes aren't freely available, even if we find the current leaders trustworthy. The current administration in the Whitehouse is trying desperately to dismantle the sweeping powers to exercise drone strikes without oversight [3], because the next administration doesn't feel as trustworthy to them.
I don't know that there is any downside to having the NSA know everything about you now. I don't know that it will be a bad idea within the next administration. But I know that it's a bad idea to let any random person have that trust, and I don't know that the election system has enough safeguards to prevent abuse by the next person elected. Or the next. Or the next.
[1] https://www.washingtonpost.com/news/the-switch/wp/2013/08/24...
[2] https://news.ycombinator.com/item?id=13102972
[3] https://theintercept.com/2016/12/06/after-8-years-of-expandi...
More concerning is stuff like the US Democratic National Committee emails showing up on Wikileaks. Being blackmailed, ransomed, or leaked is much more of a real threat for most people than some abstract harm that may be posed by the NSA or some ISP logging.
It seems to resonate much more with the millennial demo, as we can empathize with the struggles of journalists/activists/state-dissidents even though we may see our own data/life as in less need of securing, especially in light of the "Facebook/Google already have it so why bother?" sentiment that gets thrown around.
Rare possibility? Yes. But it’s a possibility. «Nothing to hide, nothing to fear» arguments cannot stand before this sort of scrutiny.
You'd think that the revelations about the NSA, things like the UK law that requires ISPs to collect and store your Internet browsing history would have more people "worried" but yet it's still pretty much a lost cause to try to explain to smart friends why this stuff matters.